Head-motion for concentrators.



J. F. ISBELL.

HEAD MOTION FOR CONCENTRATORS.

APPLICATION FILED SEPT- 8. 191-3 Patented Dec. 7, 1915.

I II IIIIIIIIIIIIIIII mane satires- Parana canton;

JOHN F. ISBELL, OF'LOS ANGELES,'CALIFORNIA, ASSIGNOR T0 ORR-EN ALLEN, OF DENVER, COLORADO.

HEAD-MOTION FOR CONCENTEATORS.

messes.

Specification of Letters Patent.

Patented Dec. 7 19315.

To all whom it may concern:

Be it known thatI, JOHN F. IsBELL, acitizen of the United States, residing at Los Angeles, in the county of Los Angeles and. State of California, have invented a new and useful Head-Motion for Concentrators, of which the following is a specification.

The main object of the present invention is to pro ide a head motion in which the dif ferentiation of the advancing and return strokes may be regulated or varied with great accuracy and throughout a wide range.

Other objects of the invention will appear hereinafter.

The accompanying drawings illustrate an embodiment of the invention, and referring thereto: Figure 1 is a vertical section of the head motion. Fig. 2 is a plan view thereof, the bracket for attachment to the concentrator table being shown in section. Fig. 3 is a transverse sectional view through the head motion taken on a vertical plane passing longitudinally through the adjusting screw to be hereinafter described. Fig. i is a longitudinal section of the eccentric and its bearing ring and the bearing portion of the toggle member operated thereby.

T he head motion is mounted in a suitable base or frame 1 provided with means for attachment to a suitable fixed support and with bearingsfl for the operating shaft 3 of the head motion. Said shaft 3 is provided with driving means suchas a pulley, indicated in broken lines at 4 in Fig. l. A cam or eccentric 5 is provided on theshaft 3 and a sleeve or collar 6 is rotatively mounted on and extends aroundth eccentric 5 and engages an arm or lever 8 form ing one member of a toggle, the other mem-. ber of which is formed by a link 9, said arm 8 and link 9 being connected together by a knuckle joint orpivot shaft 7 and being mounted at their outer ends on suitable bearings 10 and 11. Bearing 11 is fixed in the operation of the machine and serves as an abutment for the toggle. Bearing 10 consists of a shaft on a reel-ting frame 12 which is mounted on a fixed shaft or bearing at its lower end, and is connected I by pivot or shaft 14 at its upper end to a head 15 connected with a. bar it having connection with a bracket 17 depending from the plate 18 which is rigidly attached to the "table, indicated in dotted. lines at 19. The

bar 16 screws at oneend into the head 15 and is provided at its other end with a screw portion, engaging with nuts 20 earing on opposite faces of the bracket 17 so "that by adjustment of nuts 20, the longitudinal po sition of the table relative to the head motion-may be adjusted. llhe bar 16 extends through an opening 23 in the head motion frame land a-spring 24; engages with a seat 25 adjacent said opening and with a collar 26. held by a nut 26' screwing on the bar 16', said spring tending to draw thebar l6 and rocking lever or frame'12 so as to bend the toggle 8, 9, downwardly. The fixed bearing for the toggle comprises a shaft 11 which engages with a bearing face 27 on the frame 1 and is held in position by a tightening screw 28 fastened to the shaft 11 and extending through an opening 29 in the frame 1, said screw 28 being provided with a nut 3 O which presses a spherical collar 31 into tight contact with a bearing or seat around the opening 29, so as to draw the shaft 11 tightly against its bearing 27. The stroke of the machine depends on the vertical position of this abutment shaft 11, this vertical position being determined by the adjustment of said shaft by means of a yoke 33 connected to said shaft and engaged by a screw 34 which is rotatably mounted in the frame 1 and provided with operating means 35, the mounting of the screw 34 being sufficiently loose to permit of the slight longi tudinal motion of the yoke 33 and shaft 11 dueto the curvature of the abutment face 27 such face being approximately concentric with the center of the knuckle shaft 7 of the toggle. The lever 8 is extended beyond the knuckle shaft 7 of the toggle, as shown at 38, and a bearing face is formed on the lever and. on its extension 38 to engage thering or collar 6 on the eccentric so that as said ring or collar rises and falls on the rotary motion of the'eccentric, the lever 8 will be raised and lowered and the toggle 8, 9, will be opera'tedto produce a longi .tudinal motion of the bar 16.

in order to minimize the wear and friction on the eccentric 5, and ring 8, the said ring is provided with a forations 43 through which suitable iubri bearing sleeve 41. of bronze or other suitable metal, retained I 'in place by flanges at? and provided with percant such as graphite composition, piaced between the sleeve and the ring may find its way to the bearing surface of the cocentric.

The operation is as follows: Assuming the wardly, so as to draw the bar 16 against the action of the spring 2e and move the table tbward the head end thereof, this motion being arrested when the toggle is nearly straightened, so that the arrest of this mo' tion and the starting on the return motion are slow and easy. As the eccentric 5 moves down, the toggle member is lowered and the motion of the rocking frame 12 is reversed,

this motion being arrested when the toggle is in lowermost position, and in this posi tion a comparatively small motion of the toggle produces a considerable motion of the rocking frame 12, so that the reversal of motion'at this end of the stroke is sharp and quick. The extent to which the lever 8 will be raised fora given upwardimovement of the eccentric depends upon the location of the point of contact between the bearing ring 6 and the bearing face 40 of the lever 8. The farther this point of contact is from the pivotal bearing 10 of the lever 8,. 1 the less willbe the swinging movement of the lever for a given rise of eccentric and the location of this point of contact depends upon the curvature of the bearing face 40, so that by suitably shaping this face, I may increase or decrease the action ,or leverage on the lever 8. Furthermore, this point of contact shifts along this curved face ,40

in the operation of the eccentric, so that it is farther from the pivotal center ofv the member 8 in the descending than it is in the ascending motion of the eccentric. In -consequence of this, the motion of the toggle and of the table connected thereto is more rapid in the return stroke of the table than it is in the forward stroke, thereby increasing the differential effect and the forward,

travel of the ore. By raising or lowering the abutment shaft 11 by means of the ad- 1 justment of its controlling screw 34: and

yoke 33, the member 9 of the toggle may be brought more or less into line with the member 8 by any given position of the eccentrio, so that the toggle action may be varied withip considerable limits.

The bearing face 40 on the toggle member 8 is concavely curved so as to provide a better bearing on the bearing ring 6 and also to shift the point of contact more rapidly with change in position of the eccentric. In this shifting of the point of contact, the bearing ring 6 rolls on the bearing face 4:0, the only sliding movement being that which takes place within the said bearing ring due to rotation of the eccentricwithin said ring, and this sliding movement is rendered substantially frictionless by the antifriction sleeve 41.

What I claim is:

1. A head motion comprising a base, a.

shaft for the base, means to turn the shaft, an eccentric mounted on the shaft, toggle members pivoted together and operated by the eccentric, a yoke adj ustably connected to the base, a shaft mounted on the yoke and engaging oneof the toggle members and also engaging the base, ascrew fixed to the yoke shaft and provided with a collar engaging the base, a nutscrew threaded on said screw and seated against the collar, and a movable member connected to the other toggle member.

2. A head motion comprising a base having a curved seat, an eccentric rotatively mounted in the base, means to turn the eccentric, toggle members pivoted together, means'connected to one of the togglemembers to force, the toggle pivot toward the eccentric, a shaft forming an abutment for the other toggle member and resting against and adjustable along the curved seat, and means to lock the shaft firmly against said curved seat.

3. A head motion comprising a base, an eccentric rotatively mounted'on the base, means to turn the eccentric, a rocking frame pivoted to the base, a toggle member pivoted at one end to the rocking frame and provided with a downwardly curved bearing face extending from the opposite end of said toggle member toward the pivot of said toggle member, a secondtoggle member, a

pivot connecting one end of the second toggle member to the first toggle member at a point between the ends of the first toggle member, anabutment for the opposite end of the second toggle member, and means to shift said abutment relative to a vertical plane passing through the aXis of the eccentrio.

In testimony whereof, I have hereunto set my hand at 'Ielluride, Colorado, this 4th day of August, 1913.

' JOHN F. ISBELL. In presence of A. IV. Sncnnnnne, M. F. BALLEW. 

